21940265 has 8 divisors (see below), whose sum is σ = 26353728. Its totient is φ = 17535280.

The previous prime is 21940241. The next prime is 21940267. The reversal of 21940265 is 56204912.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21940265 - 2⁶ = 21940201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21940267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7844 + ... + 10266.

It is an arithmetic number, because the mean of its divisors is an integer number (3294216).

Almost surely, 2^21940265 is an apocalyptic number.

It is an amenable number.

21940265 is a deficient number, since it is larger than the sum of its proper divisors (4413463).

21940265 is a wasteful number, since it uses less digits than its factorization.

21940265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4239.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21940265 is about 4684.0436590621. The cubic root of 21940265 is about 279.9500973992.

The spelling of 21940265 in words is "twenty-one million, nine hundred forty thousand, two hundred sixty-five".